ered what could make it; how
it came there. The sun shone bright through the window; the boy moved
several things in the room, so as to place them sometimes between the
light and the colours which he saw upon the floor, and sometimes in a
corner of the room where the sun did not shine. As he moved the
things, he said, "This is not it;" "nor this;" "this has'n't any thing
to do with it." At last he found, that when he moved a tumbler of
water out of the place where it stood, his rainbow vanished. Some
violets were in the tumbler; S---- thought they might be the cause of
the colours which he saw upon the floor, or, as he expressed it,
"Perhaps these may be the thing." He took the violets out of the
water; the colours remained upon the floor. He then thought that "it
might be the water." He emptied the glass; the colours remained, but
they were fainter. S---- immediately observed, that it was the water
and glass together that made the rainbow. "But," said he, "there is no
glass in the sky, yet there is a rainbow, so that I think the water
alone would do, if we could but hold it together without the glass. Oh
I know how I can manage." He poured the water slowly out of the
tumbler into a basin, which he placed where the sun shone, and he saw
the colours on the floor twinkling behind the water as it fell: this
delighted him much; but he asked why it would not do when the sun did
not shine. The sun went behind a cloud whilst he was trying his
experiments: "There was light," said he, "though there was no
sunshine." He then said he thought that the different thickness of the
glass was the cause of the variety of colours: afterwards he said he
thought that the clearness or muddiness of the different drops of
water was the cause of the different colours.

A rigid preceptor, who thinks that every boy must be idle who has not
a Latin book constantly in his hand, would perhaps have reprimanded
S---- for wasting his time _at play_, and would have summoned him from
his rainbow to his _task_; but it is very obvious to any person free
from prejudices, that this child was not idle whilst he was meditating
upon the rainbow on the floor; his attention was fixed; he was
reasoning; he was trying experiments. We may call this _play_ if we
please, and we may say that Descartes was at play, when he first
verified Antonio de Dominis bishop of Spalatro's treatise of the
rainbow, by an experiment with a glass Globe:[8] and we may say that
Buffon w